Info What does this mean?
A status message, not a fault. It usually clears on its own and needs no action from you.
Fronius Inverter STATE 108 Error: Meaning, Causes & Safe Fix
STATE 108 means the inverter detected stand-alone (islanded) operation — it believes the grid is gone — and disconnected as a safety measure. It reconnects automatically when the grid returns.
What should I do first?
Two quick questions — we'll point you to the right starting point.
Is this code still showing on your inverter's display?
Is your system producing power right now?
What this code means
The inverter's anti-islanding protection detected stand-alone operation, i.e. it appears to be running isolated from the public grid (for example during a power outage). Disconnecting is the legally required safety response, so the inverter cannot energize a dead grid. Like all Class 1 statuses this is typically temporary: the inverter monitors the grid and resumes feeding power automatically once grid conditions are back within the permitted range.Common causes
- A grid outage or power cut in your area (most common)
- Utility maintenance work on the local grid
- A tripped main breaker isolating the inverter from the grid
Safe steps to try
Work top to bottom, ticking off each step as you complete it. 0 of 4 done.
Is your inverter still under warranty?
Before paying for a repair, check — your installer may fix this free.
Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.
When to call an electrician
If the code keeps recurring while your grid supply is normal, contact your system installer. During an actual power outage, no action is needed — the inverter will reconnect by itself.
Frequently asked questions
Why did my inverter shut off during a power cut?
That is the anti-islanding protection working as designed — it is dangerous and illegal for an inverter to feed power into a dead grid. It reconnects automatically when the grid returns.
Is stand-alone operation dangerous?
The shutdown itself is the safety measure. Do not try to force the inverter back on during an outage.
How do I clear STATE 108?
You don't need to — it clears automatically once the grid is back within limits. A persistent 108 with a healthy grid means calling your installer.
Sources: meaning and troubleshooting verified against the manufacturer's documentation — Fronius Primo 208-240 Operating Instructions, 42,0410,2116 (EN-US) — Status Codes, Class 1